Nowadays, with the increasing popularity of the applications of smart card, devices based on the MMC/SD (Multimedia Card/Secure Digital memory Card) interface are widely used in various fields. Traditional devices with the MMC/SD interface are mainly terminal devices (master devices, such as computer, handset and so forth) and memory card (slave devices, such as the MMC card, the SD card and so forth). Generally, the MMC/SD interface is used as the channel through which a master device reads/writes data from a slave device, that is, it is used in the master/slave mode (in other words, all communications are initiated by the master device). FIG. 1 is a typical flow chart of the signaling interaction of the MMC/SD interface. As shown in FIG. 1, the master device sends a CMD command, and then the slave device sends a response ERS. If there is data required to be transmitted, such data will be present on the data line of the interface. There are two kinds of data communications, READ and WRITE. The MMC/SD protocol defines 64 commands (CMD0-CMD63), part of which are reserved or assigned for particular purpose. Meanwhile, the MMC/SD protocol also defines that the communication data of the MMC/SD interface are transmitted in the unit referred to as “block”. The size of a block is 2n×512 bytes, which can be set by the master device with a CMD16 (SET_BLOCKLEN) command. The operations of READ and WRITE can be performed with a single block or multiple blocks. Each READ or WRITE command may have parameters indicating the starting address of the READ/WRITE operation and the number of blocks to be read or wrote. Additionally, the read or write operation can be stopped by a CMD12 (STOP_TRANSMISSION) command. After each data transmission, the master device can obtain the current status of the slave device with a CMD13 (SEND_STATUS) command. This communication mode have high transmission rate, but its application field and functionality are limited.
With the rapid popularity and expansion of electronic network technology, various applications based on the Ethernet platform are emerging increasingly. The Ethernet based on TCP/IP protocol is a LAN technology which is most widely used today. FIG. 2 is a figure showing a typical structural model of the Ethernet based on the TCP/IP protocol. As shown in FIG. 2, the TCP/IP protocol stack typically includes an application layer, a transport layer, a network layer, a data link layer, and a physical layer. Generally, the physical layer interface is mainly in the form of a PCI network card, a USB network card, an optical fiber card, etc. Up to now, the MMC/SD interface has not been used as the network physical layer interface.
However, if the MMC/SD interface can not be used in the network communication, the advantages of the interface, such as high efficiency and simplicity, can not be fully utilized. Therefore, there is a need for providing an Ethernet communication method and system based on the MMC/SD interface.